A comparison of the metabolic profile on intact tissue and extracts of muscle and liver of juvenile Atlantic salmon (Salmo salar L.) – Application to a short feeding study

The metabolite profiles from muscles and livers of Atlantic salmon were investigated using high resolution nuclear magnetic resonance (HR-NMR) spectroscopy of aqueous extracts and magic angle spinning (MAS) NMR spectroscopy of intact tissues. Comparison of the data showed that most small metabolites present in the aqueous extracts were also identified in the Carr–Purcell–Meiboom–Gill (CPMG) MAS NMR spectra of the intact tissues. Not only the total omega-3 fatty acid content, but also the EPA and DHA content, in the muscle and liver tissues could be calculated directly from the diffusion-edited MAS NMR spectra without the need for lipophilic extraction. The effect of replacing a normal fish meal during a period of 3 months with a diet containing 20% zygomycete was also investigated by multivariate analysis of the NMR spectra. Principal component analysis (PCA) was used to study the small metabolites distribution in the aqueous extracts of liver and muscles, and revealed that the feed containing zygomycete could have an influence on the metabolites profiles of juvenile Atlantic salmon.